The present invention relates to a self-propelled lawn mower. In a more specific aspect, the present invention relates to a self-propelled lawn mower capable of propulsion in both forward and reverse modes of operation. In still another aspect, the present invention relates to a forward and reverse propulsion system which may be readily incorporated in a standard lawn mower as an original option or added, as a modification, to an existing conventional lawn mower.
In the prior art, numerous propulsion systems have been devised and a large number of these have been and are being commercially produced.
One such system involves the utilization of a gear box or transmission containing appropriate toothed or friction gears. There are obvious disadvantages to such systems. First and foremost is the cost of such a system, which is generally so high that the inclusion thereof on a conventional, homeowner's mower cannot be economically justified, even when the transmission is designed for simple forward propulsion. Secondly, such transmissions add one more item to malfunction or fall into disrepair and which cannot be repaired by the ordinary homeowner or mechanic. This is not a rare occurrance when one recognizes that such transmissions are usually designed and manufactured with an eye to economy rather than durability. Further, the very nature of such systems requires that they be incorporated in a mower specifically constructed for transmission drive and at the factory. Hence, they cannot be installed on existing mowers or mowers designed to be hand-propelled.
Another common type of propulsion system is one in which a pair of friction rollers are engaged with either the front or rear wheels of the mower. This is generally accomplished by fixedly mounting the friction rollers on the ends of a driven rod or axle and actuating a control mechanism of some type to bring the friction rollers into contact with the driven wheels of the mower. This arrangement has a number of advantages over the transmission-operated system. The friction roller-driven wheel arrangement is, of course, more economical. Secondly, it can be factory installed on standard design mowers and in most cases can be added to an existing commercially available mower. However, Applicant is aware of no friction roller-driven wheel system which is adapted to be propelled in reverse in addition to forward.
The transmission-operated system can, of course, be propelled in both the forward or reverse modes, and sometimes is. However, the addition of a reverse drive mode simply doubles the problems, of this type system, which were previously pointed out. In addition, there is normally no means to prevent the system from being accidentally put in reverse. This is a consideration of no small moment, when one recognizes the number of accidents which are normally attributable to conventional mower operation, without reverse propulsion. Further, such systems are generally operated by a simple lever which can easily be accidentally bumped and put in reverse drive or can be readily put in reverse drive simply by someone forgetting which direction to move the lever, as a result of the usual, occasional periods of use of the mower.
It is, therefore, an object of the present invention to provide an improved self-propelled lawn mower. Another object of the present invention is to provide an improved self-propelled mower operable in either the forward or reverse mode. Yet another object of the present invention is to provide an improved self-propelled mower which is simple, economical and safe. Another and further object of the present invention is to provide an improved propulsion system for a mower which can be readily added to a standard design mower, of the rotary- or reel-type, either at the factory or by the owner. Another object of the present invention is to provide an improved mower, having both forward and reverse modes of propulsion, which cannot be accidentally or inadvertantly put into the reverse drive mode. A still further object of the present invention is to provide an improved mower having both forward and reverse modes of propulsion and in which the reverse mode of propulsion operates at a lower speed than the forward propulsion. Another object of the present invention is to provide an improved mower which can be shifted from the forward to the reverse modes of propulsion quickly.